deps(rust): update hashbrown requirement from 0.14.0 to 0.15.0

Updates the requirements on [hashbrown](https://github.com/rust-lang/hashbrown) to permit the latest version.
- [Changelog](https://github.com/rust-lang/hashbrown/blob/master/CHANGELOG.md)
- [Commits](rust-lang/hashbrown@v0.14.0...v0.15.0)

---
updated-dependencies:
- dependency-name: hashbrown
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.toml

@@ -77,7 +77,7 @@ tss-esapi = "^7.2.0"
 sketching = { path = "./src/sketching" }
 tracing-forest = "^0.1.6"
 rusqlite = "^0.32.0"
-hashbrown = { version = "0.14.0", features = ["serde", "inline-more", "ahash"] }
+hashbrown = { version = "0.15.0", features = ["serde", "inline-more", "ahash"] }
 lru = "^0.12.3"
 kanidm_lib_crypto = { path = "./src/crypto", version = "0.7.0" }
 kanidm_utils_users = { path = "./src/users" }